Kenneth Clarke, the minister without portfolio, missed the Commons vote on the motion authorising military action in Syria for 'logistical family reasons', a spokeswoman said.

Clarke, who attended the National Security Council meeting that approved the government's plans, was "fully supportive" of the government motion, she said.

International development secretary Justine Greening and junior foreign minister Mark Simmonds also failed to vote, because the bell that alerts MPs of a division was apparently not rung.

It is understood Greening and Simmonds were in a room near the Commons chamber discussing a different foreign policy matter, but because the clerks failed to ring the bell they were not aware the vote was taking place.

Both MPs voted against the Labour amendment at 10pm, which called for "compelling evidence" the Assad regime was behind the chemical attack.

But Simmonds then apparently asked to speak to Greening about a separate Foreign Office issue and the pair went to a meeting room – a small room near the chamber which ministers often use between votes.

Once there, they apparently did not hear the bell for the second vote.